The series centers on Timmy Turner, a young boy who is neglected by his parents and tortured by his babysitter, Vicky. One day, he is granted two fairy godparents, Cosmo and Wanda, who grant his every wish to improve his miserable life. However, these wishes inadvertently causing problems that Timmy must fix. In the beginning of the series, Timmy's babysitter Vicky was the main antagonist. As the series progressed, more villains were added. For example, his teacher, Mr. Crocker, firmly believes in fairy godparents and has been searching for them a very long time, correctly suspecting that Timmy has fairy godparents. He is dangerous to Timmy because, according to "Da Rules", a large rulebook that defines what children can and cannot wish for and how fairy godparents must behave, no one else can know about his fairy godparents, or else they will be taken away from him (although he does not remember, Cosmo and Wanda were once Crocker's fairy godparents, as the rule does not apply to people who currently have their own or once had fairy godparents).

At his school, Timmy is often bullied by Francis, a vicious boy who claims to be the toughest student in school, but reveals to Timmy that he only takes out his anger on him because of his rough home life and abusive parents, proving he is somewhere in-between as a protagonist and an antagonist. Jorgen Von Strangle, an enormous and tough fairy with an Austrian accent, often described like Arnold Schwarzenegger, personally dislikes Timmy and his fairies, but often has to assist them in fixing their problems.

Later in the series, Timmy wished that Cosmo and Wanda would have a baby, whom they later named Poof. More recently, Timmy got a pet fairy dog named Sparky. For every fairy, there is also an anti-fairy. The anti-fairies are similar to the real ones, but with opposite personalities and character traits. For example, Anti-Cosmo is intelligent and speaks with an English accent while real Cosmo is dim-witted. Similarly, Anti-Wanda is also dim-witted and speaks with a Southern American accent while Wanda is intelligent. When Poof was born, his anti-fairy was created. Anti-Poof's name is Foop (Poof spelled backwards). While Poof is a sphere in body-shape, Foop is instead shaped like a cube. Foop's goal in life is to cause mayhem and destroy his nemesis Poof.

The Fairly OddParents is set in the fictional city of Dimmsdale which, as revealed in the special "Fairy Idol", is located along the coast of California. The city appears to be average sized, with a downtown containing large buildings and a city hall but also containing uptown areas with residences (including the house where Timmy and his parents and godparents live) and businesses (including Timmy's school; a hospital; stores; a sports complex named the Dimmadome, named after its founder and owner; the local TV channel; and various restaurants and stores) as well as a park in the center of the city. The city also appears to have rural farmland located somewhere outside of the city. The adults in the city are notably moronic and often settle situations with things like angry mobs, but they do still form a structured and complex society capable of working as a city. In the episode "Which Witch is Which", it was revealed that Dimmsdale was founded in the 1630s after Dale Dimm managed to defeat a witch hunter who was secretly a witch named Alden Biterroot (ancestor of Denzel Crocker).

When the show needs to, it switches its location to Fairy World, the magical realm and home of the fairies which is a floating world located within the sky and colored with an abundance of pink. The fairies have a civilization like that of the humans, but with a source of power being magic, which also keeps the world afloat. A large rainbow acts as the bridge between Fairy World and the Earth. Another location sometimes seen is the city of Chincinatti, the home town of Timmy's favorite comic book superhero, the Crimson Chin. Other locations include the dark and twisted Anti-Fairy World, the dark counterpart of Fairy World where the anti-fairies live, the dull and gray metropolis of Pixies Inc., home of the pixies, and Ugopatamia, where an alien, Mark Chang, lives, who is also Timmy's friend.

A postcard for The Fairly OddParents segment on Nickelodeon's Oh Yeah! Cartoons

Producer Butch Hartman originally created The Fairly OddParents as a seven-minute short film entitled "Fairy Godparents", one of 39 short cartoons in the first season of Fred Seibert's Oh Yeah! Cartoons. Butch Hartman made six more short films for the show in season 3. Nickelodeon agreed to a six episode order (consisting of two 11-minute stories) of "The Fairly Oddparents", which began airing on March 30, 2001, in the half hour after Invader Zim.

Unlike the half-hour series, the animation in the shorts is not as smooth, and the designs are notably different (including Timmy's parents, Mr. and Mrs. Turner, who are only seen from the neck down with their faces hidden in the pilot episodes and appear to be more intelligent than they appeared to be in the proceeding series, yet still easily duped by Vicky's abhorrent actions). Other notable differences include the voices like Timmy Turner, who was voiced by Mary Kay Bergman instead of Tara Strong. Cosmo is significantly more intelligent than he appears to be in the proceeding series. Wanda is shown to be less intelligent and less of a nag. Vicky is much less evil than in the current series. She also calls Timmy by his name as opposed to the more often used "twerp".

Originally, Hartman wanted Timmy to wear a blue hat, but since he ran out of blue ink, he decided to make it pink. Wanda was originally going to be named "Venus", but instead named her Wanda. Her middle name was and still is "Venus."

The Fairly OddParents was immediately popular, greatly increasing its lead-in rating from Invader Zim. In fact, no matter what time slot Nickelodeon placed the show in, Nick's ratings soared. The series attracted a wider than anticipated audience, appealing to all ages, a feat only matched by SpongeBob SquarePants.[5] Other than SpongeBob, it was later Nickelodeon's highest rated show. Early 2002 and 2003 was the first peak of popularity for The Fairly OddParents. Ratings skyrocketed, and it briefly passed SpongeBob SquarePants.[6] The series appeared in a $50 Best Western travel card during summer 2006 and again in summer 2007.[7]

A theatrical movie film was planned for release by Paramount Pictures and Nickelodeon Movies, but it was eventually dropped because of a management change at Paramount, although the script was written. Hartman stated on his website[8] that he would like to release the film on DVD one day, but there were not definitive plans to do so.[8]

On January 24, 2006, Butch Hartman announced on his forum that Nickelodeon had ceased production of the show. "The Jimmy Timmy Power Hour 3: The Jerkinators" was intended to be the fifth season finale and series finale in production order, airing on July 21, 2006. However, Nickelodeon broadcast the episode "Timmy the Barbarian!/No Substitute for Crazy!" after "The Jerkinators" as the fifth season finale, on November 25 of that year.

Hartman announced on his forum on February 2, 2007 that Nick granted Fairly OddParents twenty more episode slots and that the show resumed production.

After a one-year hiatus, Nickelodeon announced on TV that they would begin the broadcast of a television movie called Fairly OddBaby as the beginning of at least 20 episodes of Season 6, and to carry the show to at least the year 2011.[9] A huge hit, Fairly OddBaby aired on February 18, 2008, becoming the top entertainment program across broadcast and basic cable TV for the year among kids.[10]

On March 14, 2012, the series was renewed for a ninth season with new episodes that were scheduled to broadcast that year.[11] Additionally, the second live action film, A Fairly Odd Christmas, aired in November 2012. The ninth season premiered the same day as the 2013 Kids Choice Awards. The new season introduces the new main character, Timmy's fairy dog, Sparky. Season nine is also the first season to be formatted in high definition. In 2013, it was announced there would be a third installment called A Fairly Odd Summer with Drake Bell and Daniella Monet reprising their respective roles. The movie premiered on August 2, 2014.[12]